Rounded Corner wall. Not all sides of the block. Example, if you have a hallway with a sharp turn this block could smooth that corner. Would also be Great for Art Deco designs. FW & HW would be AWESOME!!!! Maybe described as a Vertical Curve or Quarter or Half Round?

For the corners of the walls themselves, if that's what you meant, rounded drywall edge beads would also suit a Mediterranean or Adobe styles too. Huckster house being the prime example currently in-game, though Modern House probably could possibly be renovated to suit a similar Pueblo/Adobe-like style.

I'd also like to see the ability to modify both interior and exterior corners to either have wood trim - in plain wood or molding trim that coordinates with the existing wall molding, especially if they add some more wood toned molding- or no trim with differing corner shapes. This would be amazing especially if some stucco texture is added as an option for the paint colors).